The best piece of advice I can give on this is that when you are using a narrative tool, use it in a consistent way. Keeping it consistent is the most important part of any artistic endeavor. Even if you do something weird and incorrect, as long as you do that thing the same way every single time you do it, the audience will forgive for it.
When shifting POV, maybe use italics or some other obvious formatting to ease the reader into what you are doing and allow them to easily identify when you are changing POV.
I would recommend that you start your story with the non-1st Person Perspective with the different formatting so that upfront the reader is open to another point-of-view. From there, ease the reader into the 1st Person Point of View with a direct signal, "This is your narrator. This is what he was thinking at that moment..."
If you did it the other way of starting in First person and then pulling out into 3rd...you'd have to be quite the wordsmith to be able to keep an audience's attention. When a reader is used to even a chapter of hearing a character's 1st person narration, the move to 3rd person will be really jarring.
The key is to clarify for the reader who is talking when.